Vaccines continue to play an important role in the control of feline infectious diseases in an overall preventative health care program for cats. Veterinarians have succeeded in greatly reducing the incidence of vaccine-preventable diseases by establishing vaccination protocols and educating clients about the importance of vaccines. This document is intended to promote understanding and provide guidance for the use of currently available feline vaccines.

Vaccinations should be selected for each patient based on risk of exposure to specific pathogenic agents. It is impractical to recommend a standard vaccination program for all cats, because the risk of acquiring a specific infection varies due to the age and health of the patient, exposure to other cats, and geographic prevalence of disease. A comprehensive physical examination of each patient at least yearly is important to reassess its health and address possible lifestyle changes that could affect vaccine recommendations for that year. Owing to the ubiquitous nature and the seriousness of infection with feline panleukopenia (FPV), feline viral rhinotracheitis (FHV-1), feline calicivirus (FCV), and rabies, all cats should be vaccinated against these diseases. Vaccines against these diseases will be referred to as CORE vaccines. Vaccines against chlamydiosis, FeLV, FIP, and ringworm will be called NON-CORE vaccines. Use of NON-CORE vaccines should be restricted to those cats with realistic risk of exposure to these pathogenic organisms.

Vaccines should be used in accordance with principles of immunology to allow for maximum protection against disease. Factors that affect the immune response to vaccines should be considered prior to vaccine administration. (See Table, "Causes of Vaccination Failure.") The directions for use provided by the manufacturer are recommendations based on experimental evidence the manufacturer collected to support USDA approval of its products. The administration information contained in the product insert does not represent legal mandates or requirements for administering a particular vaccine. The AAFP/AFM Guidelines may differ from recommendations outlined in manufacturers' product inserts and are intended to represent the new guidelines of practice for vaccination.

Annual revaccination has been the profession's standard. More recent information suggests that duration of immunity (DOI) - at least for certain antigens - exceeds 1 year for many feline vaccines used today. Therefore, the panel recommends booster intervals for vaccines against FPV, FHV-1, and FCV every 3 years. Veterinarians may elect to vaccinate more frequently, based on the risk assessment of their patients. Cats at high risk of exposure, such as those entering boarding facilities, may benefit from more frequent revaccination. DOI studies indicate that 3 year rabies vaccines demonstrate effective immunity (see 'Feline Vaccination Protocol' Chart, p. 28).

Vaccination can cause both minor and, rarely, serious side effects. Public awareness and controversy about vaccine safety has increased, especially because of information on vaccine-associated sarcomas. Although sarcomas have been associated with the use of parenteral vaccines, the vaccination of cats at risk for specific preventable diseases should continue. Vaccination sites have been standardized to better understand the cause of sarcomas and to facilitate treatment (see Vaccine Site Recommendations, Appendix B). The use of intranasal vaccines should be considered as an alternative to the use of parenteral vaccines whenever an approved product is available.

Veterinarians have the responsibility to advise clients that vaccines are part of an overall wellness program for cats and to educate clients so they can make informed decisions. Owners should understand that the use of vaccines will help protect their cats from most signs of disease, but that vaccine-induced immunity does not always prevent infection or all signs of disease. Discussing the risks and benefits of vaccination will allow the client to give informed consent or refusal of vaccination. Legal counsel recommends that documentation of this discussion and the owner's informed decision should be recorded in the patient record.

While vaccine administration is not an innocuous procedure, the benefits of vaccination far outweigh the risks for the majority of cats. We must continue to vaccinate our patients to prevent recrudescence of infectious diseases we now control. The objective of feline vaccination protocols should be to vaccinate more cats in the population, vaccinate individuals less frequently, and only for the diseases for which there is a risk of exposure and disease.